Apparatuses for creating heat seals in sections of polymeric film packaging material located between adjacent bundles of one or more workpieces are known in the art. One such apparatus includes a support frame, a conveyor system for moving bundles of workpieces along a generally horizontal first path extending from a first end of the support frame to a second end of the support frame, and a heat seal device mounted on the support frame for creating heat seals in sections of the polymeric film material located between adjacent bundles. The heat seal device includes a carriage which is horizontally movable back and forth along a portion of the first path. A heat seal bar and anvil are mounted to the carriage for vertical movement toward and away from the first path and one another such that when the heat seal bar and anvil capture film material located between them they create a heat seal in the film material.
Horizontal movement of the carriage back and forth along the first path and vertical movement of the heat seal bar and anvil toward and away from the first path is effected via one or more conventional DC motors and mechanical elements including, e.g., one or more cams. The horizontal movement of the carriage and the vertical movement of the heat seal bar and the anvil are defined by the mechanical elements. Thus, once the shape and profile of the mechanical elements have been formed, the path along which the carriage moves and the paths along which the heat seal bar and anvil move, which latter two paths have both horizontal and vertical components, are substantially fixed and can only be changed by physically removing the old mechanical elements and substituting new mechanical elements having different shapes and profiles in their place. Accordingly, this drive arrangement has been found to be disadvantageous as it provides for very little versatility.
Accordingly, there is a need for an improved heat seal apparatus having a drive arrangement which allows the horizontal movement of the heat seal carriage and the vertical movement of the heat seal bar and anvil to be easily changed such that the paths along which the heat seal bar and anvil travel can be easily varied.